Generally, exercise machines, including but not limited to treadmills, stair steppers, and elliptical trainers, permit a user to exercise within a small, predetermined space and in a controlled manner. These devices allow a user to exercise indoors and have a number of benefits, including eliminating the effects of adverse weather conditions, allowing users to modify resistance and incline for more rigorous training, enhancing user privacy and security, and avoiding the impact of exercising on pavement, which many people find to be difficult on knees and other joints. However, exercise machines may prove difficult to use, particularly for individuals recovering from surgery, or for those with conditions that affect balance and motor control. Many exercise machines increase the risk of falling; for example, individuals with neurodegenerative diseases, such as Machado-Josephs disease, suffer from degraded muscle control and coordination and the movement of the machine exacerbates these issues. At the same time, exercise can be particularly beneficial for individuals with such physical conditions.
Many exercise machines incorporate side rails that allow a user to grip the machine for balance, reducing the likelihood that the user will fall. However, there is a temptation for a user to hold on to the side rails of the machine continually during exercise. Unfortunately, holding onto the side rails of an exercise machine during exercise is less beneficial than allowing the user's arms to move naturally during exercise. Typically, when holding on to the exercise machine users burn fewer calories, stress on various joints (e.g., hips, knees, and shoulders) is increased, and the body's balance is undermined while exercising. Unfortunately, many users need to hold on to one or more of the side rails of the exercise machine in order to maintain balance and stability to avoid injury.